1073-07-0Relevant articles and documents
Moon,Ganz
, p. 465 (1969)
Gargano et al.
, p. 389,390-396 (1975)
A General Strategy for Open-Flask Alkene Isomerization by Ruthenium Hydride Complexes with Non-Redox Metal Salts
Lv, Zhanao,Chen, Zhuqi,Hu, Yue,Zheng, Wenrui,Wang, Haibin,Mo, Wanling,Yin, Guochuan
, p. 3849 - 3859 (2017)
A homogenous metal hydride (M?H) catalyst for isomerization normally requires rigorous air-free techniques. Here, we demonstrate a highly efficient protocol in which simple non-redox metal ions as Lewis acids can promote olefin isomerization dramatically with a commercially available RuH2(CO)(PPh3)3 complex in an open-flask system. Isomerization can be accomplished within a short time, and a satisfactory selectivity for different types of unsaturated compounds can be obtained. Meanwhile, an excellent turnover number up to 17208 was achieved under air, and open-flask gram-scale experiments further demonstrated the efficiency of the RuH2(CO)(PPh3)3/non-redox-metals system. We used FTIR spectroscopy, GC–MS, NMR spectroscopy and kinetics studies to evidence that in the sluggish RuH2(CO)(PPh3)3 catalyst, bloated PPh3 ligands cause steric hindrance for the coordination of the free alkene. Alternatively, the addition of non-redox metal ions could induce the dissociation of the PPh3 ligand to offer unoccupied coordination sites for the alkene and to form the Mg-bridged adduct OC?Ru?H2?Mg2+ as the highly active species, which benefited the isomerization significantly through the metal hydride addition–elimination pathway. Finally, this strategy was demonstrated as an impactful approach for hydride catalysts of other transition metals such as Os.
Selective Isomerization of 1,5-Cyclooctadiene to 1,4-Cyclooctadiene Catalyzed by Bis(acetylacetonato)nickel-Triethyldialuminum Trichloride-Phosphorus Ligand
Sakakibara, Yasumasa,Yamamoto, Isao,Sasaki, Ken,Sakai, Mutsuji,Uchino, Norito
, p. 2236 - 2241 (1991)
The isomerization of 1,5-cyclooctadiene (1,5-COD) with Ni(acac)2-Et3Al2Cl3-phosphorus ligand (Ni:Al2:P = 1:10:3) was first examined with varying P ligands in toluene in order to find suitable conditions for the formation of 1,4-COD.The product distribution depended largely on the P ligands.For several phosphites possessing very strong ?-acceptor properties, the main product was 1,4-COD.In particular, the less-bulky bicyclic phosphite, 4-ethyl-2,6,7-trioxa-1-phosphabicyclooctane (L-3) was very effective and gave 1,4-COD in a high selectivity of 93 percent at 66 percent conversion (1,5-COD/Ni = 500, molar ratio) by employing a low temperature of -30 deg C.However, the reaction stopped before reaching completion because the catalyst was deactivated by the accumulation of 1,4-COD product.The conversion, depending on the 1,5-COD/toluene ratio (volume) rather than the 1,5-COD/Ni ratio, increased with a decrease in the 1,5-COD/toluene ratio and was 66-69 percent at a ratio of 0.19.On the other hand, the catalyst (P: L-3) was much less active for 1,4-COD than for 1,5-COD and was deactivated quickly under the same reaction conditions.This appeared to result in a high selectivity of 1,4-COD in the isomerization of 1,5-COD.The mechanistic implications of the experimental results are discussed.
Hydrogenation with Anthranilic Acid Anchored, Polymer-Bound Nickel Catalysts
Holy, Norman L.,Shalvoy, Richard
, p. 1418 - 1420 (1980)
A NiII polymer-bound catalyst was prepared by anchoring anthranilic acid to chloromethylated, highly crosslinked polystyrene beads and then equilibrating with NiCl2*6H2O.By treating this catalyst with sodium borohydride, a second catalyst was prepared.Both nickel catalysts are active in the hydrogenation of alkenes and dienes and in the reduction of nitrobenzene.The structures of the catalysts were probed by XPS studies.
Shrinivasan
, p. 3318,3321 (1964)
Ruthenium Complexes with Diazadienes VII. 1,5-Cyclooctadiene-1,4-diaza-1,3-diene Hydridoruthenium Complexes (COD)(DAD)Ru(H)Cl: Synthesis, Structure and Catalytic Properties
Dieck, Heindirk tom,Kleinwaechter, Ingo,Haupt, Erhard T. K.
, p. 237 - 248 (1987)
Displacement of piperidine from Ru(COD)(piperidine)-trans-(H)Cl (I) by 1,4-diaza-1,3-dienes (DAD: RN=CR'CR'=NR) gives the complexes cis-Ru(COD)(DAD)(H)Cl (III).With relatively bulky DAD ligands the complexes III are unstable and are converted into compounds IV, which are also formed from III on heating.Complexes III are not accessible from Ru(COD)(DAD)Cl2(V).If the analogous starting material involving a cycloheptatriene Ib in place of the COD ligand is used, a piperidide anion is preserved as a ligand instead of a hydride.In the room temperature 1H NMR spectra of rigid asymmetric III all twelve hydrogen atoms of the COD ligand can be seen separately.A full assignment has been made by use of 2D-H/H-correlated spectra.The highest field resonance (1.2 ppm) is assigned to an olefinic H atom, shielded by the DAD chelate.Complexes III catalyse the isomerization of terminal alkenes to a cis/trans mixture (20/80) of internal alkenes.During the catalytic hydrosilylation of 1-alkenes this isomerization is a competing side reaction.Thermal decomposition of III gives free 1,3-COD; the decomposition under hydrogen gives cyclooctane stoichiometrically.In catalytic experiments III is found to catlyse the isomerization of 1,5-COD to 1,3-COD via 1,4-COD.Under hydrogen pressure (20 bar), III catalyses the hydrogenation of 1-hexene and cyclohexene.Four different ways in which one, two,or three 'vacant site' can be generated starting from III are discussed.
Redox and Acid–Base Properties of Binuclear 4-Terphenyldithiophenolate Complexes of Nickel
Koch, Felix,Berkefeld, Andreas,Schubert, Hartmut,Grauer, Claudius
, p. 14640 - 14647 (2016)
This work reports on the redox and acid–base properties of binuclear complexes of nickel from 1,4-terphenyldithiophenol ligands. The results provide insight into the cooperative electronic interaction between a dinickel core and its ligand. Donor/acceptor contributions flexibly adjust to stabilize different redox states at the metals, which is relevant for redox reactions like proton reduction. Proton transfer to the [S2Ni2] core and Ni?H bond formation are kinetically favored over the thermodynamically favored yet unproductive proton transfer to ligand.
Selectice Hydrogenation of Cyclooctadienes Using Colloidal Palladium in Poly(N-vinyl-2-pyrrolidone)
Hirai, Hidefumi,Chawanya, Hitoshi,Toshima, Naoki
, p. 682 - 687 (1985)
Selective hydrogenation of 1,3-, 1,4-, and 1,5-cyclooctadiene to cyclooctene was carried out at 30 deg C under atmospheric hydrogen pressure using colloidal palladium which was prepared by reducing palladium(II) chloride with refluxing methanol in the presence of poly(N-vinyl-2-pyrrolidone).The yields of cyclooctene were 99.9percent and 97.8percent for hydrogenation of 1,3- and 1,5-cyclooctadiene, respectively at the point that an equimolar hydrogen was uptaken by cyclooctadienes.The hydrogenation rate of 1,3- and 1,4- cyclooctadiene (R1) is expressed as R1=k1, and that of 1,5-cyclooctadiene (R2) is expressed as R2=k20.7, where k1 and k2 are the rate constants.Alcohols were found to be good solvents for hydrogenation.In particular the fastest rate and the highest selectivity for monoene were observed in methanol among the solvents examined.Effect of bases on the monoene selectivity has also been investigated.
Phenylacetaldehyde as an Effective Additive for the Selective Hydrogenation of Some Nonconjugated Dienes to Monoenes over Palladium Catalysts
Nishimura, Shigeo,Ishibashi, Masayoshi,Takamiya, Hiroshi,Koike, Naomi,Matsunaga, Tadashi
, p. 167 - 170 (1987)
Methyl linoleate and 1,5-cyclooctadiene are hydrogenated with high selectivity to the corresponding monoenes over palladium catalysts in the presence of added phenylacetaldehyde, with almost complete depression of the hydrogenation to the saturates.
New biobased tetrabutylphosphonium ionic liquids: Synthesis, characterization and use as a solvent or co-solvent for mild and greener Pd-catalyzed hydrogenation processes
Hayouni, Safa,Robert, Anthony,Ferlin, Nadège,Amri, Hassen,Bouquillon, Sandrine
, p. 113583 - 113595 (2016/12/16)
Phosphonium-based Ionic Liquids (PhosILs) with natural organic derived anions (l-lactate, l-tartrate, malonate, succinate, l-malate, pyruvate, d-glucuronate, d-galacturonate, ferulate, p-coumarate) were easily prepared by acid-base method from tetrabutylphosphonium hydroxide and an excess of the corresponding acid with good yields. Their characterization was realized through classical NMR, IR and elemental analysis techniques; their viscosity and ATG parameters were also determined. These ionic liquids showed good performance and recyclability in the selective Pd-catalyzed hydrogenation of alkenes, polyenes like linoleic acid and enantioselective hydrogenation of unsaturated ketones such as isophorone at room temperature under atmospheric H2 pressure. Furthermore, NMR studies leading to computational calculations were performed to establish easily the composition of the resulting mixture obtained through the hydrogenation of linoleic acid.
